package map;

import java.util.HashMap;
import java.util.Map;

public class MapDemo11 {
    public static void main(String[] args) {

        Map<String,Integer> map=new HashMap<>();
        Integer value=map.put("语文",99);
        System.out.println(value);
        map.put("数学",99); 
        map.put("英语",99);
        map.put("物理",99);
        map.put("化学",99);
        System.out.println(map);
        value=map.put("物理",60);
        System.out.println(map);
        System.out.println(value);



        value=map.get("化学");
        System.out.println(value);
        value=map.get("体育");
        System.out.println(value);

        int size=map.size();
        System.out.println("size:"+size);

        boolean ck=map.containsKey("语文");
        System.out.println(ck);

    }
}
